a former navy s.e.a.l. who surviveed four combat tours in iraq and along the way became the most lethal sniper in american military history has been murdered in texas. authorities in lancaster, texas, have charged another former iraq war veteran with killing chris kyle and a friend yesterday afternoon. last year kyle went public with his story showing a riveting account on the battle goudfield in a memoir, "american sniper." he sat down with me, about dangers he could never have matched here the home he was celebrated for the number of kills he made from behind the scope of his sniper rifle. at least 160. a number chris kyle told me a year ago was not the one he focused on. >> if i could figure out the number of people i saved, that's something i would brag about. >> reporter: after leaving the navy nf 2009, he start add security company in his native texas. it was on a shooting range 50 mimes out of fort worth that chad and his friend were chots o shot to death. a former marine arrived with them and killed